Re: [PATCH 1/2] KVM: TDX: Handle TDG.VP.VMCALL<GetQuote>

[Huang, Kai]

On Wed, 2025-04-02 at 00:53 +0000, Huang, Kai wrote:
> > 
> > KVM forwards the request to userspace VMM (e.g., QEMU) and userspace VMM
> > queues the operation asynchronously.  
> > 
> 
> I think the key is GetQuote is asynchronous therefore KVM will return to guest
> immediately after forwarding to userspace.  Whether *userspace* queues the
> operation asynchronously doesn't matter.
> 
> > After the TDVMCALL is returned and
> > back to TDX guest, TDX guest can poll the status field of the shared-memory
> > area.
> 
> How about combing the above two paragraphs into:
> 
> GetQuote is an asynchronous request.  KVM returns to userspace immediately after
> forwarding the request to userspace.  The TDX guest then needs to poll the
> status field of the shared buffer (or wait for notification if enabled) to tell
> whether the Quote is ready.

I was thinking too quickly (since needed to pickup kids) and missed that it is
*userspace* who makes the GetQuote asynchronous.  Sorry for the noise and please
ignore the above comment :-)